Method for packaging

ABSTRACT

Hermetically sealed package for photographic sheet materials provided with one or two tearstrips which extend at the end of the package in the form of a loop. In order to facilitate the opening of the package in the dark a small part of the package is scored in the corners where the tearstrip extends, so that it can easily be torn off whereupon a sufficiently long extremity of the tearstrip is freed to open the package without difficulty.

United States Patent [191 Smolderen et al.

[451 Mar. 5, 1974 METHOD FOR PACKAGING [75] Inventors: Albert EmielSmolderen, Aartselaar;

Joseph Marie Cappuyns, Berchem, both of Belgium [73] Assignee:Aiga-Gevaert N.V., Mortsel,

' Belgium [22] Filed: Oct. 26, 1971 [21] Appl. No; 192,021

[30] Foreign Application Priority Data Oct. 26, 1970 Great Britain50,835/70 521 U.S.Cl. 53/14, 53/133,93/1 TS,

229/86 51 Im. c ..B65b61/18 58 Field of Search 53/14, 133; 93/1 TS;229/86 5 6 References Cited UNITED STATES PATENTS 5,411,263 11/1968Smolderen 53/28 2,109,505 3/1938 Rue et al 93/1 TS 180,773 8/1876Magruder 229/86 FOREIGN PATENTS OR APPLICATIONS Germany.... 93/1 TSPrimary ExaminerTravis S. McGehee Assistant ExaminerJohn Sipos Attorney,Agent, or Firm William' l. Daniel [57] ABSTRACT Hermetically sealedpackage 'for photographic sheet materials provided with one or twotearstrips which extend at the end of the package in the form of a loop.In order to facilitate the opening of the package in the dark a smallpart of the package is scored in the corners where the tearstripextends, so that it can easily be torn off whereupon a sufficiently longextremity of the tearstrip is freed to open the package withoutdifficulty.

4 Claims, 5 Drawing Figures PATENTED 51974 3. 795 O80 SHEET 2 BF 4PATENTED 74 SHEET 3 [IF 4 PATENTED 51914 sum u or 4 METHOD FOR PACKAGINGThe present invention relates to a packaging method for sheet materialas, e.g., photographic sheet material wherein at least one tearstrip isfitted at the innerside of the package.

A method for packaging photographic sheets is known comprising the stepsof tightly enclosing the photographic sheets between two rectangularsheets of wrapping material cut from webs of such material, and securingthe marginal portions of these sheets of wrapping material together,e.g., by adhesion or heatsealing. A tearstrip which has been provided atthe innerside of one longitudinal margin of the wrapping permits theeasy opening of the package. Such a packaging method has been describedin our US. Pat. No. 3,41 1,263.

The package can be opened by pulling away a corner of the wrapping atoneextremity of the longitudinal margin where the tearstrip is provided.Since the tear- A strip passes through such corner piece and is attachedthereto, said corner piece providesfor a firm hold when tearing upthelongitudinal margin of the wrapping by means of the tear stripwhereby a free access to the packaged sheets is obtained.

Such a known package suffers from the drawback that the location of thecorner piece to be torn away may involve difficulties in identifyingsame when the package must be opened in the dark. Further, the commonpractice of incorporating aluminum foil in the packaging materialincreases the resistance to tearing of the package. In such occurrencesone may have to revert to the use of a pair of scissors, in order toseparate the corner piece from the package.

The object of the packaging method according to the present invention isto provide a package which can be opened in the dark in a simple waywithout any auxiliary means.

According to the present invention, a method for packaging sheets,wherein said sheets are packaged in packaging material which forms awrapping round the sheets which is closed by flap portions at twoopposite edges of the sheets, and wherein at least one tearstrip isinserted between the packaging material and the packaged sheets, saidtearstrip extending from one flap portion to the other,.is characterisedin that a loop of said tearstrip is punched through one side of at leastone of said flap portions. Preferred but optional features of theinvention are as follows.

The tearstrip is adhered to the innerside of the packaging materialbefore the sheets to be packaged are placed thereon, and the loopin thetearstrip is punchedimmediately before the tearstrip is adhered to thepackaging material.

A slit is cut in a flap portion of the package at a loca tion close to atearstrip and'at the side thereof remote from the edge of the package,the slit extending generally parallel to the tearstrip and having alength which is smaller than the width of the flap portion.

In the present specification the term sheets applies to one single sheetonly, as well as to stacks of sheets. The sheets may be oflight-sensitive material, such as photographic paper or film, and alsoof material for use in electrophotography, such as paper coated with asemi-conducting material, or even common paper.

The packaging material may be in the form of sheets, but the packagingmaterial may also be in the form of rial and a secondweb 23 of wrappingmaterial, are

webs onto which sheets or stacks of sheets to be packaccording to FIG.2.

FIG. 4 shows apackage produced according to the method of the invention,and

FIG. 5 illustrates more clearly a corner of the package of FIG. 4.

' The embodiment of FIG. 1 comprises a basic part 10, a support 11mounted at one side on said basic part and several smaller supports atthe opposite side on said basic part for supporting several parts of theapparatus.

The rollers 12 and 22 are freelyrotatable and they bear cores onto whicha first web 13 of wrapping matewound respectively. Two rollers 14 and 15are mounted so that they are freely rotatable and hold each a roll ofsmall tapes l6 and 17, respectively.

Two welding means 18 and 19 comprise each an electric heating elementwhich heats a metal core ending in the welding pins 20 and 21. Said pinsexert a pressure on the side of the web 13 opposite to the side which,together with the tapes l6 and 17, is passed over the free-turningroller 24.

Between the roller 14 and the welding pin 20 and be tween the roller 15and the welding pin 21 respectively a punch is fitted at either side ofthe web 13, as indicated by the numeral 50. l

The punch 50 is attached to a piston 51 of a cylinder 52 and serves thepurpose'of simultaneously perforat ing the web 13 and pressing a loop ofabout 10 to 20 mm long in the tape 16 respectively 17 through theperforation 29 of the web 13. For the sake of clarity only one punchingdevice is illustrated on FIG. 1. The shape of the punch is shown in moredetail on FIGS. 2 and 3.

It can be seen that the first folding members 25 and 26 fold the marginsof the web 13 upwardly over Second folding means 27, 28 fold theextremities of said upwardly folded margins again over 90 so as tolocate them in a horizontal plane.

Stack positioning means is provided which is indicated by the numeral 30and which in a known way comprises two parallel rows of vertical fingerswhich cyclically can approach horizontally to each other over a givendistance and then remove vertically from the web, so as to properlyalign the sheets of the stacks, which the operator has been placed onthe web between the said fingers in the longitudinal direction of theweb and to properly space the successive stacks on the web.

A roller 31 which is stationarily fitted on a freeturning shaft 32presses on the central part of the stacks as they pass under it. Thestacks are flexed thereby, since the upper side of the basic part 10 isprogressively concavely curved in the transverse direction from behindthe stack positioning means 30 up to the said roller 31, and theupstanding portions of the second folding members 27 and 28 slightlyapproach towards each other.

The second web 23 of wrapping material is passed over the free-turningroller 33 and it is applied with its margins onto the folded extremitiesof the margins of the first web.

The welding means 34 and 35, provided with welding pins similar to thoseof the welding means 18 and 19, exert a pressure on the margins of theweb 23.

After said welding means 34, 35 the concavity of the upper side of thebasic part of the apparatus progressively diminishes, and at the placeof the transport port roller system 36, the said upper side hasrecovered into its 'flat form.

The roller system 36 comprises two horizontal rows of driven rollerswhich engage a wrapped stack at either side thereof in order to advancethe webs at a uni form speed and to flatten the stack, therebytensioning the wrapping around the stack.

The transverse sealing means 37 comprises an upper transverse sealingbar 38, moved by a pneumatic cylinder 39, and a cooperating lowersealing bar (not shown) which can approach towards each other and pressonto each other in a plane which is located half the height ofthe-wrapped stacks. In a known way the sealing bars are provided attheir cooperating faces with an electrically heated flatresistance'wire, which is covered with a strip of Teflon fabric (Teflonis registered trade mark of E. I. du Pont de Nemours & Co., Wilmington,Del., U.S.A.). As indicated in FIG. 5, the sealing means 37 is effectiveto produce a crimped seal extending in the form of a band transverselyacross the assembled webs between successive sheets.

A transverse cutting means 40 comprises an upper severing knife 4] movedby a pneumatic cylinder 42 and a cooperating lower knife (not shown)which can approach towards each other so as to separate the successivepackaged stacks.

Next to the transverse cutting means 40 an auxiliary cutter (not shown)may be mounted in such a way that a corner piece of the sealed part canbe cut half-way or scored close to the spot where the loop of-one of thetapes 16 and 17 is pressed through the perforation to the outer side ofthe web 13 by means of the punch 50. g

The auxiliary cutter cooperates with the cutting means The sealing means37 and the cutting means 40 are both mounted on a carriage 43 which issupported by guide rails 44. The carriage is cylically moved to the lefthand side, according to FIG. 1, at the speed of travel of the webs overa distancewhich is shorter than thedistance between two successivestacks, and thereafterit is returned at increased speed to the righthand side, according to FIG. '1, in order to start a next cycle. Thesaid movements are imparted to the carriage by the chain. beingcyclically driven by motor means in either direction. Motor means of thepresent kind are well-known in the art and have. therefore not beenrepresented here.

The operation of the apparatus for wrapping stacks of radiographic filmsheets, each stack containing-125 sheets of NIF (non-interleaved filmfilm of 10 X 8 inches, a protective card-board sheet being provided ateither side of the stack, will now be described.

The first web 13 has a width of 34 cm, the second web 23 has a width of25 cm. Both webs are composed of three adhering superposed layers, viz.an opaque paper layer, an aluminium layer and a black polyethylenelayer. Suchlike materials permit to package film sheets so that they arefully protected against moisture, chemical vapours and light. The web 13is wound on the roll 12 the polyethylene layer at the inside, the web 23is wound on the roll 22 the polyethylene layer at the outside.

The tapes 16 and 17 consist of a tough kind of paper, they have a widthof 3 mm and a thickness of some tenths of a millimetre.

The webs 13 and 23 are continuously pulled from the rolls 12 and 22 bythe driven rollers 36 being always in contact with at least one wrappedstack.

The operator places a stack of sheets on the advanc ing web 13 betweenthe positioning'rneans 30, the longitudinal direction of the sheetsextending transversely of the web. The opposed transverse edges of thesheets engage the upstanding marginal portions of the web 13. The tapesl6 and 17 remain in place at the inside of the upstanding marginalportions of the web when inserting the stack since they have beensecured to the polyethylene layer of the web 13 by means of the weldingpins 20 and 21 which weaken the polyethylene layer and press the webagainst said tapes. The opposed longitudinal edges of the sheets of thestack are aligned by the stack positioning means 30 which after thealigning operation vertically remove from the web so as to let the stackpass by.

The stack of sheets is continuously advanced in flat condition by theweb 13 until reaching the flexing roller 31. Immediately before thisroller is reached the extremities of the upstanding margins of the .web13 have come into contact with the second folding members 27, 28 whichprogressively fold said'extremities towards each other. 4

The lower part of the roller 31 extending beneath the top side of thestack engaging its periphery, causes the stack to flex so as to make itpass under the roller. The flexing of the stack is permitted by theconcave upper side of the basic part 10 as described hereinbefore.

The flexing of the stack is assisted by the vertical portions of thefolding members 27, 28 which slightly converge so as to exert pressureon the opposed edge faces of the stack.

- When passing under the roller 33, the extremities of the margins ofthe first web 13 have been folded on top of the stack in one plane andthe second web 23 is applied onto said folding extremities.

As the stack is still flexed, it passes under the sealing means 34, 35.Near its both extremities the web 23 is heated by the sealing means 34,35 over a small path, so that its thermoplastic layer at the oppositeside softens. Together with the pressure exerted by the sealing means, atight joint is formed between the extremities of both webs. Thetensioning of the webs in the longitudinal direction suffices to ensurea sufficient stiffness of the web portions between the successive stacksso that the webs are also well sealed to each other at those areas whenpassing under the sealing means 34, 35.

After said sealing means 34, 35 the concavity of the upper side of thebasic part 10 gradually decreases, as mentioned already hereinbefore.When reaching the transport roller system 36 (in the drawing thedistance between the sealing means 34, 35 and the roller system has beenreduced considerably) the wrapped stack is flattened and the wrappingtensions around the stack.

When the wrapped stack is leaving the roller system 36, the last rollerpair thereof still engaging the stack,

I then the carriage 43 has been located'in the position most to theright according to the figure. A magnetic valve is opened, andair-pressure is admitted to the cylinder 39 so that the sealing bar 38and the cooperating lower sealing bar approach to each other and weakenand seal the web portions extending just in front of the wrapped stackin a direction normal to that of the tearstrip. The opening of the valvemay be triggered by sensing means 47 comprising a microswitch which isactuated'by a lever, said lever being strongly biased so that the smallroller, fitted at its extremity and running over the lower web,depresses slightly the web when a it. Said roller is positioned at about0.5 cm after the vertical plane through the two sealing bars, and as itdepresses the web when rolling over the trailing edge of the precedingstack, the sealing bars seal the webs right web portion between twosuccessive stacks passes over in the middle of the spacing between saidpreceding also the means driving the carriage was started and thecarriage 43 moves to the left at a speed equal to that of the webs. Theelectric circuit of the magnetic valve controlling the cylinder 39remains closed by a delaying relay so that when the small roller rollson the following stack, the sealing means remains operative.

After moving over a distance of about five centimetres the carriage, byan upstanding leg, actuates the microswitch 48, the electric contact ofwhich controls a magnetic valve in the air-pressure supply of thecylinder 42. The transverse cutting means 40 is operated and separatestwo successive packages. The closed A package 80 produced according tothe present invention is shown in FIG. 4. At one end of bothlongitudinal sides the loop 70 formed by the perforation of the web 13during the punching process emerges from the heat-sealed portion 72 atabout to mm from the edge.

The structure of a corner is more clearly illustrated in FIG. 5. In theheat-sealed portion 72 of the package 80 a small portion 73 limited bythe incision 71 is cut out to about half of the thickness withoutaffecting however the light-tightness of the package.

The package according to FIG. 4 is opened as follows. The packageistaken, e.g.,.with the left hand and the half-way cut corner piece 73 atthe right hand bottom place according to FIG. 5 is gripped with thumband fore-finger of the right hand. The corner piece 73 is very easilytorn off the package 80 by a simple separation movement of the hands.

' In doing so a free extremity of the tape 17 is realized which issufficiently long, which can be easily held and with which the bottompart of the package 80 (see contact of the microswitch 48 furtherenergizes a relay which breaks theele'ctric circuit of the magneticvalve controlling the cylinder 39 so that the transverse sealing means37 becomes inoperative.

' The mentioned relay also reverses the drive sense of 10mm from theplace where the package is cut through,

by the cutting means 40. The width of the weld obtained with the sealingmeans 37 is thus defined that the perforation made bythe punch in-theweb 13 through which the loop of the tape 16 respectively 17 is passingare located within the weld limits. In this way the tightness to air andto moisture of the package remain intact.

FIGS. 2 and 3 illustrate respectively a more detailed lateral andtransversal view of the punching device. Ac-

tuation of the punch 50 is obtained by admitting pressurized airpassinto the cylinder 5 52, causing a piston located in the cylinder tomove downwards and to perforate the web 13. This actionis facilitatedwith the help of two tapered points 54 and 55. At the same time thestubbed part 56 between said points grips the tape 17 thus forming aloop in same in the hole 58 during a very short time lapse. The punchingdevice is fixed on a support 53.

FIGS. 4 and 5) can be opened without difficulty; Thereupon the operatorcan gently take the sheets of the photographic material out of thepackage.

The tearstrips 16, 17'may be applied at only one' side of the stacks.Feeding means mayflbe provided for feeding other strips, sheets or websin the package, e.g. colour strips for characterizing the type ofmaterial contained in the package, thin lead foils in the packaging ofsingle radiographic film sheets for use as intensifying screen, etc.

Finally, means may be provided for automatically fee'dingthe sheets orthe stacks of. sheets to be wrapped successively onto the first web, sothat the apparatus may operate completelyautomatically.

. We claim:

1. In a method of wrapping flexible sheets, by the steps of feeding thesheets to be wrapped in successive spaced relation on a first travelingweb of wrapper material, conveying a second web of such material abovethe path of said sheets in generally synchronous relation with theirtravel with said first web, folding opposite marginal portions of atleast one of said webs inwardly over said sheets and inwardly contiguousweb portions, securing together said contiguous web portionsprogressively along the length of the webs, sealing together the firstand second web over transversely extending sealing bands situatedbetween successive sheets, and finally severing the thus wrapped sheetsfrom the traveling web assembly, along tranverse lines within saidsealing bands, the improvement of laying a tearstrip ribbon on the uppersurface of said first web along a line inwardly proximate to at leastone of the marginal portions of said first web, advancing said web andtearstrip ribbon to a punching station, at said punching stationsimultaneously punching at each of successive spaced intervals alongsaid web between 4 said sheets a slit opening in said web and deflectingsaid tearstrip ribbon through said slit opening in the form of ing bandsare formed by crimping the webs together with heating, with the crimpedcorrugations rtmning generally normal to the direction of web travel,and said scoring extends generally perpendicular to said corrugations.

1. In a method of wrapping flexible sheets, by the steps of feeding thesheets to be wrapped in successive spaced relation on a first travelingweb of wrapper material, conveying a second web of such material abovetHe path of said sheets in generally synchronous relation with theirtravel with said first web, folding opposite marginal portions of atleast one of said webs inwardly over said sheets and inwardly contiguousweb portions, securing together said contiguous web portionsprogressively along the length of the webs, sealing together the firstand second web over transversely extending sealing bands situatedbetween successive sheets, and finally severing the thus wrapped sheetsfrom the traveling web assembly, along tranverse lines within saidsealing bands, the improvement of laying a tearstrip ribbon on the uppersurface of said first web along a line inwardly proximate to at leastone of the marginal portions of said first web, advancing said web andtearstrip ribbon to a punching station, at said punching stationsimultaneously punching at each of successive spaced intervals alongsaid web between said sheets a slit opening in said web and deflectingsaid tearstrip ribbon through said slit opening in the form of a loopprojecting from the opposite side of the web, the spacing of saidsuccessive intervals coinciding with said sealing bands and each sealingband being of an extent in the direction of web travel such that thecorresponding slit opening and loop are within its confines.
 2. A methodaccording to claim 1 comprising adhering the tearstrip to said uppersurface of said first web before the sheets to be packaged are placedthereon and at a point immediately downstream of said punching station.3. A method according to claim 1 comprising scoring said sealing band ofthe package in inward proximity to said tearstrip ribbon along a lineintersecting said severance line and terminating within the sealingband.
 4. A method according to claim 3 wherein said sealing bands areformed by crimping the webs together with heating, with the crimpedcorrugations running generally normal to the direction of web travel,and said scoring extends generally perpendicular to said corrugations.